When in use, spark plugs experience explosive forces generated from the combustion of fuel within the combustion chamber. These explosive forces are exerted against the portions of the spark plug that project into the combustion chamber, including the exposed portion of the insulator. The unexposed portion of the insulator is held in place by the spark plug shell within a bore of the cylinder head. The explosive forces are exerted against the exposed portion of the insulator while the unexposed portion of the insulator is held in place thereby resulting in a bending moment or force on the insulator, which can result in weakening or fracturing of the insulator.